What are the treatment options for managing psoriasis?

Psoriasis Management

For chronic plaque psoriasis, initiate treatment with high-potency topical corticosteroids (clobetasol 0.05% or betamethasone dipropionate 0.05%) combined with calcipotriol twice daily for 2-4 weeks, achieving 58-92% clearance rates, then transition to weekend-only corticosteroid application with weekday vitamin D analogs for maintenance. 1, 2

Initial Assessment and Diagnosis

• Diagnosis is clinical based on characteristic erythematous, scaly plaques in typical distributions—laboratory investigations are rarely helpful and should not delay treatment. 3, 4

• Assess severity using two components: the patient's perception of disability (their "need for treatment") and objective body surface area involvement using body mapping or PASI scoring. 3

• Screen for triggers and exacerbating medications including alcohol, beta-blockers, NSAIDs, lithium, chloroquine, and mepacrine—the latter three can cause severe, potentially life-threatening deterioration. 3, 5

• Evaluate for comorbidities including psoriatic arthritis, cardiovascular disease, obesity, metabolic syndrome, diabetes, and depression, as psoriasis severity correlates with MI-related mortality. 6, 7, 4

Topical Therapy Algorithm for Mild-to-Moderate Disease

First-Line Treatment (Body Plaques)

• Apply clobetasol propionate 0.05% (ultra-high potency) or betamethasone dipropionate 0.05% (high potency) twice daily to thick plaques for maximum 2-4 weeks. 1, 5

• Combine with calcipotriol (vitamin D analog) either as separate products or fixed-combination formulations for synergistic effect superior to either agent alone. 1, 2, 5

• Add tazarotene (topical retinoid) with moderate-to-high potency corticosteroids for body plaques to reduce irritation while enhancing efficacy. 1, 5

Location-Specific Modifications

• For face, genitals, intertriginous areas, and forearms: Use low-potency corticosteroids (class 5-7) or topical calcineurin inhibitors (tacrolimus 0.1%, pimecrolimus) to minimize atrophy risk. 1, 5

• For scalp involvement: Apply clobetasol propionate 0.05% shampoo twice weekly, leaving on scalp 5-10 minutes before rinsing, providing rapid relief within 3-4 weeks. 1

• For thick, non-responding plaques: Consider intralesional triamcinolone acetonide up to 20 mg/mL every 3-4 weeks on glabrous skin, scalp, nails, palms, and soles. 1

Mandatory Safety Protocols for Topical Corticosteroids

• Conduct regular clinical review every 4 weeks during active treatment with no unsupervised repeat prescriptions for high-potency agents. 3, 1

• Limit moderate-potency corticosteroid use to maximum 100g per month and require dermatological supervision for class 1-2 (very potent/potent) preparations. 3, 1

• Plan annual periods employing alternative non-corticosteroid treatments (coal tar, dithranol, vitamin D analogs) to prevent continuous high-potency steroid exposure and associated complications including skin atrophy, striae, telangiectasia, and HPA axis suppression. 3, 1

Maintenance Phase Transition

• After achieving control at 2-4 weeks, transition to weekend-only corticosteroid application while using vitamin D analogs on weekdays to maintain disease control while minimizing adverse effects. 1, 2, 5

• Taper frequency gradually rather than abrupt withdrawal to prevent rebound flare phenomenon. 1

Alternative Topical Agents

Coal Tar

• Start with 0.5-1.0% crude coal tar in petroleum jelly, increasing concentration every few days to maximum 10%—cruder extracts are messier but more effective than refined products. 3, 5

• Coal tar is extremely safe and appropriate for long-term use when corticosteroid breaks are needed. 3

Dithranol (Anthralin)

• Begin at 0.1-0.25% concentration, increasing in doubling concentrations as tolerated, with careful explanation of irritancy and staining of skin/clothes. 3

• Use "short contact mode" (15-45 minutes every 24 hours) for great benefit with reduced side effects. 3

• Exercise extreme caution on face, flexures, and genitalia due to heightened irritancy risk. 3

Special Considerations for Guttate Psoriasis

• Recognize guttate psoriasis as typically self-limiting with many patients experiencing no further attacks after initial episode. 3

• Use lower concentrations of tar and dithranol as erupting lesions are less tolerant of topical treatment than chronic plaques. 1

• Consider narrowband UV-B phototherapy as especially helpful for guttate presentations. 1

• Investigate and treat streptococcal infection with phenoxymethylpenicillin or erythromycin in patients showing evidence of persistent streptococcal infection. 1

Escalation Criteria to Systemic Therapy

Refer to dermatology for systemic therapy when: 1, 2

• Body surface area involvement exceeds 5%
• Inadequate response to optimized topical therapy after 8 weeks
• Repeated hospital admissions required for topical treatment
• Extensive chronic plaque psoriasis in elderly or infirm patients
• Signs of erythrodermic or pustular psoriasis develop
• Severe psoriatic arthropathy present

Systemic Treatment Options for Moderate-to-Severe Disease

First-Line Systemic: Photochemotherapy (PUVA)

• PUVA is the least toxic systemic agent and generally considered first-choice systemic treatment. 3

• Start at 70% of minimum phototoxic dose (determined at 72 hours), increasing successive doses by 40% of preceding dose if no erythema, with response expected within 4 weeks. 3, 2

• Requires contraception, UV-A eye protection, and genital shielding unless specific need to treat those areas. 3

Biologic Therapy

• Adalimumab (TNF-α inhibitor) is FDA-approved for moderate-to-severe chronic plaque psoriasis in adults who are candidates for systemic therapy or phototherapy when other systemic therapies are medically less appropriate. 8

• Adalimumab achieves treatment goals in 68.2-79.3% of patients by week 16, with >93% achieving ≥75% PASI reduction. 2, 7

• Can be combined with methotrexate or topical high-potency corticosteroids for enhanced efficacy. 2

• Mandatory pre-treatment screening for active/latent tuberculosis, hepatitis B, and fungal infections due to increased risk of serious infections and malignancy. 2, 8

• Contraindications include: active infections, history of recurrent infections, heart failure, demyelinating disease, and live vaccines during treatment. 8

Conventional Systemic Agents

• Methotrexate: Response in 2 weeks; requires contraception (men and women), baseline liver function tests, full blood count, serum creatinine, and avoidance of interacting drugs. 3

• Acitretin (etretinate): Response in 6 weeks; requires contraception for 2 years after stopping treatment, baseline lipid panel and liver function tests. 3

• Cyclosporin: Response in 3 weeks; contraindicated with abnormal renal function or uncontrolled hypertension; requires blood pressure and serum creatinine monitoring. 3

• All systemic agents require dermatological supervision due to potential toxicity. 3

Critical Medications to Absolutely Avoid

• Never prescribe systemic corticosteroids for psoriasis—they precipitate erythrodermic psoriasis, generalized pustular psoriasis, or very unstable disease upon discontinuation. 2, 5

• Avoid lithium, chloroquine, and mepacrine—associated with severe, potentially fatal psoriasis deterioration. 3, 5

• Do not combine salicylic acid with calcipotriol—acidic pH inactivates calcipotriol and reduces effectiveness. 5

Common Pitfalls to Avoid

• Perceived "tachyphylaxis" to topical corticosteroids is usually poor adherence, not true receptor down-regulation—address compliance issues before switching therapies. 2, 5

• Patients failing one topical agent may respond to another—trial alternative topical agents before escalating to systemic therapy. 3, 2

• Most patients with chronic stable plaque psoriasis can be managed in primary care, but those requiring systemic agents need ongoing dermatological supervision. 3, 5